import java.util.Scanner;

public class mb008 {
    public static void main(String[] args) {
        int[] mj = {1, 3, 5, 2, 6, 9, 7};
        Scanner input = new Scanner(System.in);//创建输入
        System.out.println("请输入整数");
        int num= input.nextInt();//接收输入
        boolean  fiag = false;
        for (int i = 0; i < mj.length; i++) {
            if (mj[i]==num) {
                System.out.println(mj[i]);
                fiag=true;//真
                break;
            }
        }
        if (fiag==false){//假
            System.out.println("-1");
        }

    }
}
